I’m a Senior Full-Stack Engineer with 8+ years of experience building production-ready SaaS platforms, distributed backend systems, real-time communication products, AI voice agents, and e-commerce solutions. I help startups and established businesses turn complex ideas into scalable, reliable products—from architecture and backend services to responsive web applications, third-party integrations, deployment, monitoring, and ongoing production support. My strongest areas include: 🌐 Full-Stack SaaS Development • Java, Spring Boot, Spring Cloud, React, Next.js, TypeScript, Node.js, Python, and FastAPI • REST APIs, WebSockets, microservices, multi-tenant SaaS, admin dashboards, and internal tools • MySQL, PostgreSQL, Redis, Elasticsearch, Docker, AWS, and CI/CD 🎙️ AI Voice Agents & Real-Time Communication • AI phone agents, voice assistants, customer-service automation, and conversational workflows • Twilio, Telnyx, LiveKit, WebRTC, SIP, Asterisk, FreeSWITCH, and real-time messaging • STT, LLM, and TTS pipelines with interruption handling, DTMF, IVR navigation, call transfers, outbound calling, and low-latency audio • Integration with OpenAI, Claude, Gemini, Deepgram, ElevenLabs, and other AI providers 🤖 AI Agents, RAG & MCP • LLM-powered agents, RAG knowledge bases, workflow automation, and tool integration • Model Context Protocol (MCP) servers and tools for connecting AI agents to business systems • Agent memory, structured outputs, human approval workflows, evaluation, observability, and guardrails • n8n, Make, Zapier, CRM, email, calendar, database, and third-party API automation 🛍️ Shopify, Payments & E-Commerce • Shopify theme development, Liquid customization, responsive storefront implementation, and performance optimization • Shopify Admin API, Storefront API, webhooks, product and order integrations • Stripe, PayPal, Shopify Payments, subscriptions, refunds, reconciliation, and failure recovery • Secure webhook processing with signature verification, idempotency, retry handling, and audit logs ⚙️ Distributed Systems & Reliability • Kafka-based event-driven architecture and high-throughput messaging • Idempotency, retries, eventual consistency, distributed transactions, caching, and fault tolerance • Monitoring, logging, tracing, alerting, graceful degradation, and production incident debugging • OAuth2, OpenID Connect, Keycloak, RBAC, IAM, and multi-tenant security Relevant work includes real-time video meeting systems, online learning and e-commerce platforms, payment workflows, event-driven backend services, and AI-powered communication products. I can support the complete delivery lifecycle: • Architecture and technical planning • Frontend and backend implementation • AI, voice, payment, and third-party integrations • Production deployment and performance optimization • Debugging, modernization, and long-term maintenance If your project involves a full-stack SaaS product, AI voice agent, WebRTC platform, Shopify customization, payment integration, MCP tool, or complex backend system, I’d be happy to discuss the architecture and propose a practical delivery plan.

I am a software developer specializing in full-stack development and AI-powered solutions. I have hands-on experience building end-to-end systems, from backend services and frontend applications to AI model development and fine-tuning. My work includes automation solutions, custom AI workflows, and visual AI pipelines using tools like ComfyUI. I primarily work with Python and TypeScript, and I also have solid experience with C, C++, and C# for performance critical and system-level tasks. I focus on writing clean, scalable code and delivering practical solutions that solve real-world problems efficiently.

Most automations break in production. Mine don't. I build systems that run at 2am without anyone watching. Error handlers, dedup logic, Slack alerts when something fails. Not just demos that work once. Background: 10 years in software engineering. 4 at Tencent building systems for hundreds of thousands of concurrent users. Anthropic Certified Claude Architect (CCA-F). What I've shipped: Automation Rescue (Make + Twilio + Stripe + Airtable) - Took over a live system: 34 scenarios, 28 had never executed once. - Quick system-wide scan first: what's dead, what's fragile, what the business actually runs on. Not a month-long audit of things that may never get touched. - Then one module at a time, highest priority first. Deep audit on that module, report lands with a clear call: fix it or rebuild it, exact price and timeline attached. Client approves, I ship, client accepts. Then the next module. - Every delivery comes with a Loom walkthrough of the full test run, error handling included, plus documentation the client can hand to the next person. - Every deadline delivered early. Band Scheduling Automation (n8n + Airtable + Twilio + Google Calendar) - Leader creates a gig, picks who to invite, presses one button — availability texts go out to every musician. - Replies matched by phone number. No codes, no app, no login. Dashboard updates the moment a text lands. - Resend is safe: already-texted musicians are skipped automatically. Only the failed sends get retried. - Leader presses Confirm, Calendar event created, every confirmed musician added as an attendee, final confirmation text sent to each one. - Leader sees who's confirmed, who's pending, who said no — without touching a phone after the first button press. Lead Management System (n8n + HubSpot + Slack + GPT) - Speed-to-lead: form submits → first-touch email sent in 60 seconds. No human in the loop. - Every lead gets scored by AI and business rules together. High-value leads never get buried. Each one lands in the right bucket: hot, warm, or cold. - Hot leads ping Slack with a one-click Claim button. Sales takes over instantly. The rest get AI-drafted follow-ups on day 2, 5, and 12. - When a lead replies, follow-up stops. Three attempts, no response: break-up email sent, lead archived. - Zero duplicates. Zero leads fall through. How I work: Async by default. Daily Loom: what moved, what's blocked. Weekly Loom: full recap and next week's plan. You stay in the loop without scheduling a single call. Send me your workflow. Working demo in your inbox within 24 hours. - You Li

I build machine learning pipelines that actually work in production — not just notebooks that look good in demos. Most of my work revolves around tabular data: gradient boosting (LightGBM, XGBoost, CatBoost), tabular deep learning (TabNet, TabPFN), and causal inference. I've spent a lot of time on the unglamorous but critical parts — feature engineering, handling imbalanced datasets, model calibration, and making sure results are interpretable and reproducible. A few things I've shipped: A cancer risk prediction system for a medical research team (AUC > 0.84), with full feature importance analysis and threshold strategy reports. A 3D reconstruction pipeline based on Structure-from-Motion, robust enough to handle blurry and low-texture inputs. That work led to 2 software copyrights and a patent under review. A causal boosting framework (CBDT) for heterogeneous treatment effect estimation — benchmarked on IHDP, ACIC, and MIMIC-III. Paper currently under submission. Quantitative models for financial risk — credit scoring with XGBoost and TabNet, A/B testing on simulated datasets, ended up improving accuracy by 15% and cutting false positives by 20%. I'm comfortable working with financial data, backtesting pipelines, and building risk models from scratch. I also work with OpenClaw for robotic manipulation tasks and have experience integrating it into simulation and control workflows. On the tools side: Python is my daily driver, along with PyTorch, Transformers, Optuna, and Git. I write clean, documented code — not the kind you need to reverse-engineer to understand. I'm finishing up a B.Eng. in Software Engineering (Beijing University of Technology × UCD joint program, class of 2026). Kaggle Gold and Silver medalist. If any of this sounds relevant to what you're working on, drop me a message. I usually reply within a few hours.

I solve WordPress problems — slow sites, plugin conflicts, WooCommerce bugs, theme issues, and migrations. Two 5-star projects completed on Upwork. What makes me different from a typical WordPress developer: I automate the repetitive parts. Using n8n and API integrations, I build workflows that keep your business running without constant manual work: · WooCommerce order → auto-sync to Google Sheets, CRM, or email notification · Form submission → trigger API workflow, create task, notify your team · Content updates → auto-push to Telegram, Slack, or social channels · Daily site health checks → get alerts before your customers notice problems WordPress services I deliver: · Bug fixes & plugin conflict resolution · Speed optimization & performance tuning · WooCommerce setup, customization & payment integration · Theme customization & responsive design · Site migration & security hardening 10 years in technical project delivery. PMP certified. Clean code, tested workflows, clear documentation your team can maintain without me. Have a WordPress or automation project? Message me — I'll reply with a clear plan within 24 hours.

I am a senior full-stack development engineer with 4+ years of experience in developing large-scale enterprise applications. 🧑‍💻Has been responsible for multiple products, including but not limited to high-security applications, high-concurrency high-availability applications, B2B/B2C products, and SaaS. 🏆Previously responsible for a complex system with more than 30+ million registered users. 🛠️Proficient in the full stack technology stack: 1️⃣Back-end: Java, Python, Spring Framework, Django 2️⃣Front-end: HTML/CSS/JS, TypeScript, Vue.js, Wechat Mini Program 3️⃣tools: Git/SVN, Maven, Swagger, Nginx, RabbitMq, Docker,etc. 4️⃣DataBase: MySQL, PostgreSQ, Redis, etc. 5️⃣Design: Experience in distributed, microservices, and high-concurrency architecture design that covers almost the entire career. 💼 Just tell me what needs to be done!

Experienced back-end engineer with 10+ years of expertise in high-concurrency systems. Proficient in Golang, Python, and C++, focused on delivering scalable and efficient solutions. Advanced machine learning skills for creating intelligent, data-driven applications. Proven leader in both large companies and start-ups, driving innovation and excellence. - Ensures applications handle heavy loads efficiently. - Creates smart, adaptive, data-driven AI applications. - Skilled in AWS, Azure, and Google Cloud. - Proficient with Redis, DynamoDB, Kafka, Nginx, MySQL, Postgres, Elasticsearch. - Experienced with ReactJS, TypeScript, TailwindCSS. - Leads teams, fostering innovation and success. - Proficient in Golang, Python, C++, TypeScript, Rust, C#.

I build AI automation systems that replace manual work, streamline operations, and scale business processes. From workflow automation to AI agents and data processing systems, I deliver end-to-end solutions that actually run in production. 💡 What I Can help You I help businesses automate operations using AI and workflows: AI Automation (end-to-end business processes) Workflow Systems (n8n, Make, API integrations) AI Agents (Claude, OpenAI, OpenClaw, multi-step automation) Data Extraction (PDF, OCR, invoices, documents) Python Automation (scripts, backend logic, data processing) Messaging Automation (Telegram, WhatsApp, email systems) Internal Tools & Dashboards (web-based tools) ⚙️ Technical Stack Python (automation, data pipelines) n8n / Make (workflow orchestration) OpenAI API / Claude (AI processing) OpenClaw / Claude Code (AI agent systems) OCR (Tesseract, document parsing) REST APIs & Webhooks VPS deployment (Linux, security setup) 💬 If you want to automate workflows, build AI agents, or process business data automatically — I can design and implement a complete solution. 📺 Demos: YouTube @aiwithgrace1

I am fluent in English and bilingual in Chinese and Cantonese, which allows me to work comfortably with international and cross-border projects. I value clear communication, reliable delivery, and attention to detail. I am a business-oriented data analyst with a strong foundation in accounting and economics, currently pursuing a Bachelor’s degree in Accounting in an English-taught program. I specialize in turning raw data into clear, actionable insights that support business decisions. I have hands-on experience with Excel, Python (pandas), data cleaning, data extraction, and basic ETL workflows, including working with APIs and structured datasets in academic projects and competitions. I focus on accuracy, clarity, and practical results rather than overly complex models. What I can help you with: Data cleaning, preprocessing, and organization Excel analysis, formulas, and structured reports Python (pandas) for data analysis and automation Data extraction from files or APIs Clear analytical summaries and presentations for business use If you are looking for a responsible entry-level data analyst who understands both numbers and business logic, I’d be happy to help.

🚀 Staff iOS Engineer (10+ yrs) — Real-time Video/VoIP & AI Integration I build and fix iOS/macOS apps fast—clean, stable, and ready to ship. Previously at Fanatics (Live & Collect), Agora (macOS Tech Lead), and RingCentral (Staff Engineer). I specialize in two high-value areas: real-time audio/video systems and production AI integration. ✅ Selected impact • Reduced crash rate 10x through systematic stability work (crash/ANR triage, threading, memory) • Improved user NPS +40% via closed-loop quality optimization • Evolved a live platform from viewer-only → full broadcaster (streaming + interactions) • Built ANR monitoring (main-thread blocking detection) → 3x faster issue resolution • Experience shipping for massive-scale consumer products (e.g., bilibili-level traffic) 🎥 Real-time audio/video & streaming (production) • Live streaming & video conferencing: LiveKit / Agora SDK / Amazon IVS • AVFoundation capture/render pipelines, recording/upload, performance tuning • CallKit + PushKit VoIP calling (background, reconnect, audio routes, reliability) • Real-time interactions: auctions, voting, chat (WebSocket / GraphQL Subscriptions) • Screen sharing: iOS App Extension + macOS plugins • Socket/IM architecture experience; solid networking fundamentals (TCP/UDP) 🤖 AI integration • OpenAI / Claude API integration for user-facing features • HealthKit + Apple Watch data pipelines (sleep/HR/activity/workouts) • Prompt & context management, on-device + cloud orchestration for personalized insights 🏗️ Architecture & engineering • Clean Architecture / SOLID, protocol-oriented DI, modular design • TCA & MVVM (migration and coexistence), Swift Concurrency (async/await, Actors) • Swift + Objective-C, pragmatic refactors, long-term maintainability 🧪 Quality & delivery • Tests: XCTest/XCUITest, snapshot tests; TDD when valuable (Quick/Nimble) • CI/CD: Fastlane, Jenkins/GitHub Actions/Xcode Cloud, TestFlight/App Store release • Logging/analytics (e.g., Firebase/Crashlytics) to locate root causes quickly 🛠️ How I work • Start with a short paid assessment → confirm scope, estimate, and risks • Milestones with demos + clear acceptance criteria • Strong communication, pragmatic testing, and maintainable Swift • Available 40 hrs/week, fluent in English, timezone-friendly and responsive 💻 Equipment: Mac Studio (M1 Max, 32GB), dual 28” 4K monitors, 1Gbps fiber. If you’re building live video/VoIP features, integrating AI into an app, or need to stabilize and scale an existing codebase, feel free to message me—happy to review your scope and propose a plan.